Field of the Invention
The present invention relates generally to implantable sound sensors, and more particularly, to an implantable sound sensor for hearing prostheses.
Related Art
Implantable hearing prostheses primarily comprise an implantable stimulator that provides electrical, mechanical, optical or other stimulation to a recipient's inner and/or middle ear. Such prostheses also include a microphone, that is configured to receive and transform an acoustic sound into an electrical signal that is supplied to a sound processor. The sound processor utilizes the signal to drive the implantable stimulator.
One type of implantable hearing prosthesis, referred to as a cochlear implant, delivers electrical signals to a recipient's auditory nerves via electrodes implanted in the recipient's cochlea. The delivered electrical signals cause the recipient's brain to perceive a hearing sensation resembling the natural hearing sensation normally delivered by the auditory nerve. Another type of implantable hearing prosthesis is the auditory brainstem implant that delivers electrical stimulation signals directly to a recipient's brain, thereby bypassing the auditory nerve. A still other type of implantable hearing prosthesis is the middle ear implant that uses an actuator to provide mechanical stimulation signals (vibration) to a recipient's middle or inner ear.
In some implantable hearing prostheses, the microphone is also implanted in the recipient. Implantable microphones are conventionally implanted subcutaneously in proximity of the ear. A drawback of subcutaneous microphones is that they are sensitive to body noise which may originate from the circulatory, respiratory, skeletal, digestive or other systems.